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Y @lait-th tang garant Letters Patent No. 79,743, ata-z .my 7, 1ste.

IMPROVEBIENT IN GRATE-BARS,

@tige Stimuli referat te in 'time ttttets ateat mit mating nrt at tigt miic.

TO ALL WHOM IT MAY CONQERN.:

Be it known that I, ADDISON C. Fmrrcunmof the city, county, and State of New York, have inventeda new and useful Improvementin Grate-Bars, of which the following is a. full, clear, and exact description, .refjl erence. being had'to the'aceempanying drawing, Vvforming part of this specilicationyand in which-v Fignre 1 represents a side view of aigrate-bar constructed-in accordance with my improvement. Figure 2 is a vertical transverse section of the same through theclotted line a: x in iig. 1, -and Figure 3 a plan of several such bars as arranged side by side to form a grate. Similar letters (if reference indicate corresponding parts.

This, my invention, consists in a peculiar hook-shaped construction to fuelpoints or rests naadefin or on the upper edge ofthe bar by means of transverse recesses or air-ducts, preferably ot a conical: or lother equivalent character, and communicating or connecting at their base with channels or Ways of a rcversely-tapering or diminishing` descriptionformed inthe sides of the bars, the'hoeked-shaped constructionA of said fuel-points orvrest's serving to contribute to thedurabilit-y of the bar by establishing cooling currents ofpair througlrthem at t or below their centres; also aiding the -free circulation and supply of air to the ducts between the points; likel wise assisting to lighten the bars, andto enlarge their facility lfor expansionnithout straining or warping.

Referringto tho accompanying drawing, A represents the body ot-v the bars, said body being 1i`ormedonits`Y 'upper edge with fuel-points o r rest-s a, whicli are established-bytransverse recesses or air-ducts ci' a tapering or widening character from their throats or months c, so as to give an enlarged capacity in a gradual manner below said mouths for a free 'supply of air, and quick escape through the months' to the firebed, suclrconstruction also establishing heat-conducting and radiating points or ends, d, to theafuel-rests a for heating the air as it passes to the lire, thereby aiding the combustion, andby such abstraction of the heat,lscrving to keep the fuelresting portions vof the bar cool, andconsequently addi-ng to the durability of the bar.

Connected with the recesses or air-,ducts- 11, at their bases; aretapering or downwardly-diminishing channels or ways, e, formed alternately on opposite` sides of the bar for facilitating the escape of dust and ashesfrom the' air-duct b, and for the supply' of air to saidfdue'ts. y

' To add to the eiiciency of sucha b ar as rcgardsjits establishing' acopious or' free circulation, andnn'iform distribution-of air to the.iire,'.with increased freedom for separate expansion of `the fuel-points or rests (gse as to avoid warping of the bar, 'and better protection against burning, by cooling said points thronghza snp'plycf air to orthrongh them, contributing alike to the durability of =the bar', and heatingrof the air in its way toA thev re-bed, I give to said fuel-points 'or rests 4more or less a hook-like 'character by means of transverse branch openings,f, in communicationwiththe ducts '5, and' extending npifardly'to beneath .the centres, or thereabouts,

ofthe fuel-resting portions of the These braneli openings orhook-like shapes to the rests a `it is preferredto arrange'so that in each adjacent bar they face in opposite directions. By such Ahook-like sha-pe to thetuelpoints or rests', not only is increased durability to the'bar insured, by reason of air entering thc branches ffrom or up the channels c, and cooling the centres as it were of said rests, but'lsuch branches likewise afford addi.A tional heatingsurfaces, thus expanding the volume of heated air escaping through the mouths or throats-c, and

laterally between the bars to snpport combustion, such hook-like formation of thet`uelpoints or rests also giving greater freedom for independent e'xpansionof the latter. Y

l What is here claimed, and desired to'be secured byLet'tersv Patent, ist 1.' The reduction ofthe'fuel-bearing portions acf a grate-bar by the formation of air-ducts,f, therethrough, having communication with the main ducts b for the more thorough cooling and equalizing ofthe expansion of such portions, and increasing the air-heating surfaces, substantially as shown and described.

2. The combination of the passagesf, the channels or tva-ys e, and air-dnets '6, `with the fuel-points or rests a, all arranged snbstantiallyas shown and described. i i

.. ADDISON C. FLETCHER.

Witnesses: i Y

A. La CLERC, E. P. TRACY. 

